"There has been significant evidence collected. I will tell you that today our evidence technicians were at the scene once again and did recover a piece of significant evidence that wasn't found in the last few days," he said.

When asked for more details about what the "significant evidence" was, Filenko only added that "a human being" found it.

"We did recover a significant piece of evidence."--Cmmdr George Filenko on progress today in Fox Lake investigation. @WGNNews

The investigation and search for suspects into the killing of Lt. Charles Joseph Gliniewicz has been ongoing since Tuesday.

Earlier Friday, officials announced a $50,000 reward is now being offered for the capture and conviction of those who killed Lt. Gliniewicz.

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Illinois Manhunt, Fox Lake Police Lt. Charles Joseph Gliniewicz

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Officials say 'significant evidence' found in Fox Lake investigation

FOX LAKE, IL - SEPTEMBER 02: Residents and police from Fox Lake and surrounding communities attend a vigil for slain Fox Lake police officer Lt. Joe Gliniewicz on September 2, 2015 in Fox Lake, Illinois. Gliniewicz was shot and killed yesterday during a foot chase with three suspects who remain at large. (Photo by Scott Olson/Getty Images)

FOX LAKE, IL - SEPTEMBER 02: Officers salute as the family of slain Fox Lake police officer Lt. Joe Gliniewicz arrive for a vigil held in his honor on September 2, 2015 in Fox Lake, Illinois. Gliniewicz was shot and killed yesterday during a foot chase with three suspects. (Photo by Scott Olson/Getty Images)

Police officers meet up before heading out for a manhunt on Tuesday, September 1, 2015 in Fox Lake, Ill. (Stacey Wescott/Chicago Tribune/TNS via Getty Images)

FOX LAKE, IL - SEPTEMBER 01: Police officers search an area for suspects involved in shooting an officer September 1, 2015 in Fox Lake, Illinois. A manhunt for three suspects is underway after an officer from Fox Lake Police was shot and killed this morning. (Photo by Scott Olson/Getty Images)

FOX LAKE, IL - SEPTEMBER 01: Police officers get get a break after coming off a search mission as temperatures exceeded 90 degrees during a manhunt for three suspects in the murder of a Fox Lake Police officer on September 1, 2015 in Fox Lake, Illinois. Lt. Joe Gliniewicz was found with a gunshot wound shortly after the department lost radio communication with him during a foot chase of three suspects. (Photo by Scott Olson/Getty Images)

FOX LAKE, IL - SEPTEMBER 01: Police officers search an area for suspects involved in the shooting death of an officer September 1, 2015 in Fox Lake, Illinois. A manhunt for three suspects is underway after an officer from Fox Lake Police was shot and killed this morning. (Photo by Scott Olson/Getty Images)

FOX LAKE, IL - SEPTEMBER 01: A police sniper keeps watch from the roof of a home while other police search nearby for suspects involved in the shooting of an officer September 1, 2015 in Fox Lake, Illinois. A manhunt for three suspects is underway after an officer from Fox Lake Police was shot and killed this morning. (Photo by Scott Olson/Getty Images)

FOX LAKE, IL - SEPTEMBER 01: Police officers search an area for suspects involved in shooting an officer September 1, 2015 in Fox Lake, Illinois. A manhunt for three suspects is underway after an officer from Fox Lake Police was shot and killed this morning. (Photo by Scott Olson/Getty Images)

FOX LAKE, IL - SEPTEMBER 01: A police officers looks out across a search area as the manhunt continues for three suspects in the murder of a Fox Lake Police officer on September 1, 2015 in Fox Lake, Illinois. Lt. Joe Gliniewicz was found with a gunshot wound shortly after the department lost radio communication with him during a foot chase of three suspects. (Photo by Scott Olson/Getty Images)

FOX LAKE, IL - SEPTEMBER 01: Sisters Brittany (L) and Renee Evans join other residents in showing their support as the manhunt continues for three suspects in the murder of a Fox Lake Police officer on September 1, 2015 in Fox Lake, Illinois. Lt. Joe Gliniewicz was found with a gunshot wound shortly after the department lost radio communication with him during a foot chase of three suspects. (Photo by Scott Olson/Getty Images)

FOX LAKE, IL - SEPTEMBER 01: A police officer searches an area for suspects involved in shooting an officer September 1, 2015 in Fox Lake, Illinois. A manhunt for three suspects is underway after an officer from Fox Lake Police was shot and killed this morning. (Photo by Scott Olson/Getty Images)

A sniper and a lookout stand on top of a roof searching for two men following the killing of a police officer Tuesday, Sept. 1, 2015 in Fox Lake, Ill. (Stacey Wescott/Chicago Tribune/TNS via Getty Images)

FOX LAKE, IL - SEPTEMBER 01: Police officers search an area for suspects involved in shooting an officer September 1, 2015 in Fox Lake, Illinois. A manhunt for three suspects is underway after an officer from Fox Lake Police was shot and killed this morning. (Photo by Scott Olson/Getty Images)

FOX LAKE, IL - SEPTEMBER 01: Police officers search an area for suspects involved in the shooting death of an officer September 1, 2015 in Fox Lake, Illinois. A manhunt for three suspects is underway after an officer from Fox Lake Police was shot and killed this morning. (Photo by Scott Olson/Getty Images)

FOX LAKE, IL - SEPTEMBER 01: A police officer cools down his search dog as temperatures exceeded 90 degrees during a manhunt for three suspects in the murder of a Fox Lake Police officer on September 1, 2015 in Fox Lake, Illinois. Lt. Joe Gliniewicz was found with a gunshot wound shortly after the department lost radio communication with him during a foot chase of three suspects. (Photo by Scott Olson/Getty Images)

Police officers patrol a swampy area where a manhunt is taking place on Tuesday, September 1, 2015 in Fox Lake, Ill. (Stacey Wescott/Chicago Tribune/TNS via Getty Images)

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Motorola Solutions Inc. Vice President Ali Kapadia said at a news conference Friday that the telecommunications company was offering the reward money.

Kapadia said many of the company's employees live in the area of Fox Lake, where police Lt. Gliniewicz.